Periscope optical assembly

ABSTRACT

The present disclosure provides for periscope optical assemblies within interposers that include a bulk material having a first side and a second side opposite to the first side; a first optic defined in the bulk material at a first height in the bulk material along an axis extending between the first second sides; a second optic defined in the bulk material at a second height in the bulk material, different than the first height, along the axis; a first waveguide defined in the bulk material, extending from the first side to the first optic; a second waveguide defined in the bulk material, extending from the second optic to the second side; and a third waveguide defined in the bulk material, extending from the first optic to the second optic.

TECHNICAL FIELD

Embodiments presented in this disclosure generally relate to fabricatingfeatures in optoelectronic devices. More specifically, embodimentsdisclosed herein provide for the production of waveguide and mirrors inthe light path of the waveguides to redirect the light path.

BACKGROUND

Waveguides are optical components that confine and direct the path thatlight travels within the medium of an optical device. The opticalwaveguides define areas of increased refractive index relative to theoptical medium (e.g., SiO₂) to direct the light along a desiredtrajectory. Due to the refractive index difference of the waveguidesrelative to bulk material of the optical device, waveguides can definecurved paths that gradually shift the light from one straight path toanother.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate typicalembodiments and are therefore not to be considered limiting; otherequally effective embodiments are contemplated.

FIG. 1 illustrates a cutaway view of a periscope assembly, according toembodiments of the present disclosure.

FIG. 2 illustrates a cutaway view of a two-piece periscope assembly,according to embodiments of the present disclosure.

FIG. 3 illustrates a series of mirrors of different layouts, accordingto embodiments of the present disclosure

FIGS. 4A-4C illustrate several alignments of two mirrors and threeassociated waveguides. According to embodiments of the presentdisclosure.

FIG. 5 illustrates a reordered waveguide layout, according toembodiments of the present disclosure.

FIG. 6 illustrates a mirror arrangement, according to embodiments of thepresent disclosure.

FIG. 7 illustrates a mirror arrangement, according to embodiments of thepresent disclosure.

FIG. 8 illustrates a mirror arrangement, according to embodiments of thepresent disclosure.

FIG. 9 illustrates a mirror arrangement, according to embodiments of thepresent disclosure.

FIG. 10 illustrates a mirror arrangement, according to embodiments ofthe present disclosure.

FIGS. 11A and 11B illustrate coupling arrangements for a periscopeassembly and another optical element, according to embodiments of thepresent disclosure.

FIG. 12 is a flowchart of a method to deploy a periscope opticalassembly.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially used in other embodiments withoutspecific recitation.

DESCRIPTION OF EXAMPLE EMBODIMENTS Overview

One embodiment presented in this disclosure describes an interposer,comprising: a bulk material having a first side and a second sideopposite to the first side; a first optic defined in the bulk materialat a first height in the bulk material along an axis extending betweenthe first second sides; a second optic defined in the bulk material at asecond height in the bulk material, different than the first height,along the axis; a first waveguide defined in the bulk material,extending from the first side to the first optic; a second waveguidedefined in the bulk material, extending from the second optic to thesecond side; and a third waveguide defined in the bulk material,extending from the first optic to the second optic.

One embodiment presented in this disclosure describes a method,comprising: defining a first mirror in a bulk material at a firstheight; defining a second mirror in the bulk material at a secondheight, different than the first height; defining a first waveguide inthe bulk material, optically connected to the first mirror and a firstedge of the bulk material; defining a second waveguide in the bulkmaterial, optically connected to the second mirror and a second edge ofthe bulk material, different than the first edge; and defining a thirdwaveguide in the bulk material, optically connected to the first mirrorand the second mirror to define a light path from the first edge to thesecond edge via the first waveguide, the first mirror, the thirdwaveguide, the second mirror, and the second waveguide.

One embodiment presented in this disclosure describes a system,comprising: a first waveguide defined in a first plane of a bulkmaterial; a second waveguide defined in a second plane of the bulkmaterial, parallel to the first plane; a third waveguide defined in athird plane of the bulk material that intersects the first plane and thesecond plane; a first mirror defined at a first intersection of thefirst plane and the third plane and optically connected to the firstwaveguide and the third waveguide; and a second mirror defined at asecond intersection of the third plane and the second plane andoptically connected to the third waveguide and the second waveguide.

EXAMPLE EMBODIMENTS

The present disclosure provides systems and methods for the creation anddeployment of periscope interposers and other optical devices usingmirrors defined in the light paths of waveguides to rapidly andcompactly redirect the direction in which light travels in the opticaldevice. By defining at least a pair of mirrors in the light path, viaetching, lithography, metal plating, chemical deposition, precisionmolding, and/or laser patterning, the periscope assembly can receiveoptical signals on one plane and redirect those optical signals toanother plane, including planes parallel to the original plane, over ashorter distance than if the waveguide were curved to direct the opticalsignals to a new plane. Additionally, by staggering several mirrors, thewaveguides can receive optical signals in a first physical arrangement,and output optical signals in a different physical arrangement.

Although the present disclosure generally provides examples related tointerposers including mirrors and waveguides as internally definedcomponents, the creation and deployment of periscope optical componentscan include additional optical and electrical elements, such as, forexample, optical gratings, phase shifters, optical filters, and thelike.

FIG. 1 illustrates a cutaway view of a periscope assembly 100 (e.g., aninterposer), according to embodiments of the present disclosure. Invarious embodiments, the periscope assembly 100 of FIG. 1 is constructedas one component made of an optical bulk material 110, such as, forexample, SiO₂, in which a first waveguide 120 a (generally, waveguide120), second waveguide 120 b, third waveguide, first mirror 130 a(generally, mirror 130), and second mirror 130 b are defined. In otherembodiments, the periscope assembly 100 of FIG. 1 represents a fullyconstructed multi-piece periscope assembly, such as is discussed ingreater detail in regard to FIG. 2.

Although generally described in relation to mirrors 130, the examplesprovided herein may be understood to include several other optics,including, but not limited to: mirrors, lenses, optical gratings,filters, and combinations thereof. The optics may be defined by variousprocesses in the bulk material 110 to have different effects on opticalsignals carried in the bulk material 110 based on the refractive indexand the angle of the light passing from one region in the bulk material110 to another. For example, a waveguide 120 may be defined to confinelight to a predefined path in the bulk material 110, whereas a mirror130 may redirect light received in one direction to a second direction.Other optics may have other effects on light carried in the bulkmaterial 110, such as a lens focusing/converging or diffusing/divergingincoming light, an optical grating splitting and diffracting light intoseveral beams, a filter removing/blocking/attenuating/polarizing certainwavelengths of light, etc.

As illustrated in FIG. 1, a first waveguide 120 a runs in parallel to asecond waveguide 120 b, and a third waveguide 120 c is optically coupledto the first and second waveguide 120 a-b via a first mirror 130 a and asecond mirror 130 b. The first mirror 130 a is defined to receiveoptical signals carried on the first waveguide 120 a and reflect thoseoptical signals onto the third waveguide 120 c. The second mirror 130 bis defined to receive the optical signals carried on the third waveguide120 c and reflect those optical signals onto the second waveguide 120 b.The mirrors 130 may have various sizes, shapes, configurations ofreflective surface, and interfaces with the waveguides 120 (e.g.,lenses, filters) in various embodiments.

FIG. 2 illustrates a cutaway view of a two-part periscope assembly 200,which, when assembled, may provide the periscope assembly 100illustrated in FIG. 1. As illustrated in FIG. 2, a first component 210 aincludes a first waveguide 120 a, a second waveguide 120 b, and a firstmirror 130 a disposed between the first waveguide 120 a and the secondwaveguide 120 b that are defined in the bulk material 110 of the firstcomponent 210 a. A second component 210 b includes a third waveguide 120c, a fourth waveguide 120 d, and a second mirror 130 b disposed betweenthe third waveguide 120 c and the fourth waveguide 120 d that aredefined in the bulk material 110 of the second component 210 b.

Various alignment features 220 a-d (generally, alignment feature 220),such as paired male and female interconnects, may be defined in and onthe bulk materials 110 of the first and second components 210 a-b(generally, two components 210) to align the second waveguide 120 b andthe third waveguide 120 c, so that when the two components 210 arejoined together, the second and third waveguides 120 b-c define onecontinuous waveguide 120. In various embodiments, the two components 210are joined together via an epoxy joint, solder, thermocompression, or adie level process to bond and secure the components together. In variousembodiments, the alignment features 220 are designed to self-alignrelative to a paired alignment feature to align the waveguides 120 inthe periscope. For example, the alignment features 220 may be formed asU-grooves, V-grooves, interlocking notches, trapezoidal features, etc.

In some embodiments, the waveguides 120 and mirrors 130 in FIGS. 1 and 2may be defined within the bulk material 110 by a three-dimensional laserpatterning process to affect the material matrix of the bulk material110 and thereby the refractive index of the material to contain light ona defined pathway as a waveguide 120, or to reflect and sharply redirectthe light onto a new pathway as a mirror 130. In some embodiments, thewaveguides 120 and mirrors in FIGS. 1 and 2 are defined via amultilayered lithographic process, or with a combination of lithographicand laser patterning processes. For example, a fabricator may use laserpatterning to define the paths of the waveguides 120, and a physicaland/or chemical etching process to define the mirrors 130. Othertechniques, such as grayscale lithography, can be used to patternthree-dimensionally sloped mirrors 130 and optics in the bulk material110.

In some embodiments, the mirrors 130 are defined as three-dimensionalreflective structures within the bulk material 110, while in otherembodiments, the mirrors 130 are defined via a reflective surfacetreatment. For example, a laser can positively define the structure of amirror 130 by imparting a region with a different refractive index fromthe bulk material 110 and the waveguides 120 to reflect optical signalsapplied thereto to a different waveguide 120. For example, a laser canalter the material matrix of a bulk material 110 such as SiO₂ to imparta region with a different reflectivity to certain wavelengths of light.In another example, a lithographic etching process can negatively definethe structure of a mirror 130 by removing bulk material 110, and afabricator can polish or apply a reflective coating applied to a surfacedefined in the etched region to define the mirror 130. Additionally,although not illustrated, a fabricator may apply a surface treatmentand/or a lens to the interfaces between two waveguides 120 to reduceback reflection and/or signal power loss when an optical signaltransitions from one waveguide 120 to another. In additionalembodiments, index matching epoxy or antireflective coatings can also beused to reduce back reflection.

FIG. 3 illustrates a series of mirrors 130 of different layouts,according to embodiments of the present disclosure. The first mirror 130a includes a flat reflective surface 310, while the second mirror 130 band third mirror 130 c include curved reflective surfaces 310. Each ofthe illustrated mirrors 130 may be understood to be a positively defined“prism” or a negatively defined “void”. When interpreted as a prism, areflective surface 310 is defined on an “exterior” surface to reflectoptical signals. When interpreted as a void, a series of walls definethe void, and a reflective surface 310 is defined on one “interior”surface of a wall to reflect optical signals. Accordingly, the secondmirror 130 b may be concave when defined by a prism structure and convexwhen defined by a void. Similarly, the third mirror 130 c may be convexwhen defined by a prism structures and concave when defined by a void.Although the present disclosure primarily illustrates the examplemirrors 130 as including flat reflective surfaces 310, a fabricator mayuse various curved surfaces when defining the mirrors 130. Additionally,although illustrated as providing one reflective surface 310 per mirror130, a fabricator may define mirrors 130 with more than one reflectivesurface 310 or mirrors 130 in which the reflective surface 310 varies inorientation and curvature at different locations.

FIGS. 4A-4C illustrate several alignments 400 a-c (generally, alignment400) of two mirrors 130 and three associated waveguides 120. Each of thealignments 400 a-c shows different reflective angles 410 a-b from themirrors 130. Although the first reflective angle 410 a and secondreflective angle 410 b for each of the alignments 400 a-c are shown asequal to each other in a given alignment 400 (e.g., both 90 degrees), afabricator may construct or angle the mirrors 130 to produce analignment 400 that includes a first reflective angle 410 a that differsfrom the second reflective angle 410 b.

Each of the alignments 400 a-c illustrates a first waveguide 120 arunning in a first direction feeding an optical signal into a firstmirror 130 a which reflects the optical signal to a second waveguide 120b running in an intersecting path to the first waveguide 120 a. Thesecond waveguide 120 b feeds the optical signal into a second mirror 130b, which reflects the optical signal to a third waveguide 120 c, whichruns on an intersecting path to the second waveguide 120 b, and may runparallel to the first waveguide 120 a on a different plane.

The alignment 400 a of FIG. 4A illustrates reflective angles thatposition the second waveguide 120 b perpendicularly to the firstwaveguide 120 a and the third waveguide 120 c (i.e., reflective angles410 of 90 (±2) degrees). The alignment 400 b of FIG. 4B illustratesreflective angles that position the second waveguide 120 b acutely tothe first waveguide 120 a and the third waveguide 120 c (i.e.,reflective angles 410 of less than 90 (±2) degrees). The alignment 400 cof FIG. 4C illustrates reflective angles that position the secondwaveguide 120 b obtusely to the first waveguide 120 a and the thirdwaveguide 120 c (i.e., reflective angles 410 of greater than 90 (±2)degrees).

A fabricator may adjust the reflective angles 410 between two waveguides120 by altering the angle of the reflective surface 310 incident to thewaveguides 120, altering the curvature of the reflective surface 310,inserting or defining a lens on or at the reflective surface 310, etc.

FIG. 5 illustrates a reordered waveguide layout 500, according toembodiments of the present disclosure. In the reordered waveguide layout500, a first plurality of waveguides are defined in a first pattern 510a at an input, and are defined in a second pattern 510 b at an output;(generally, pattern 510). As illustrated, three light paths 520 a-c(generally, light path 520) (including one or more waveguides 120 andthe associated lenses, filters, etc.) are arranged triangularly indifferent planes in the first pattern 510 a, and linearly in a sharedplane in the second pattern 510 b, but other patterns 510 arecontemplated (e.g., circular, rectangular, W-shaped, etc.).

To reorder the pattern 510 of the light paths 520, a set of staggeredand paired mirrors 130 are defined in each light path 520 to alter therelative paths of the waveguides 120 therein. For example, the firstmirror 130 a and the second mirror 130 b are disposed in the first lightpath 520 a to accept signals carried by a first waveguide 120 a in afirst plane, and direct those signals onto a second waveguide 120 b in asecond plane via a third waveguide 120 c defined between the first andsecond mirrors 130 a-b. The third mirror 130 c and the fourth mirror 130d, in the illustrated example, are disposed in the second light path 520b to accept signals carried by a fourth waveguide 120 d in a planedifferent than the first plane or the second plane, and direct thosesignals onto a fifth waveguide 120 e in the second plane (e.g., linearlyarranged with the second waveguide 120 b) via a sixth waveguide 120 fdefined between the third and fourth mirrors 130 c-d. Similarly, thefifth mirror 130 e and the sixth mirror 130 f are disposed in the thirdlight path 520 c to accept signals carried by a seventh waveguide 120 gin a plane different than the first plane or the second plane, anddirect those signals onto an eighth waveguide 120 h in the second plane(e.g., linearly arranged with the second waveguide 120 b) via a ninthwaveguide 120 i defined between the fifth and sixth mirrors 130 e-f.

Additionally, although illustrated as a polygonal to linear reordering,a fabricator may reorder a first pattern 510 a into various types,shapes, and orientations of different second patterns 510 b or alter therelative order of individual light paths 520 in the same shape ofpatterns 510 a-b in other embodiments. For example, if the first pattern510 a is a linear arrangement of a first, second, and third light paths520 a-c in a plane parallel to the xy-plane, a fabricator may define themirrors 130 such that the second pattern 510 b is also linear, butpresents the first, second, and third light paths 520 a-c in a planeparallel to the xz-plane. In another example, if the first pattern 510 ais a linear arrangement of a first, second, and third light paths 520a-c sequentially from left to right, the fabricator may define themirrors 130 such that the second pattern 510 b is also linear, butsequentially presents (from left to right) the third light path 520 c,the first light path 520 a, and the second light path 520 b.

A fabricator may deploy several different staggered mirrors 130 withdifferent reflective angles, different relative locations to the edgesof an interposer (e.g., at different x and y coordinates according toFIG. 5), and different relative heights within an interposer (e.g., atdifferent z coordinates according to FIG. 5) to affect differentreordering of patterns 510 for the incoming and outgoing waveguides 120.

FIG. 6 illustrates a mirror arrangement 600, according to embodiments ofthe present disclosure. In the mirror arrangement 600 of FIG. 6, a firstwaveguide 120 a bypasses a first mirror 130 a and optical signalscarried thereon are not reflected by that first mirror 130 a in a newdirection or plane. In contrast, optical signals carried by the secondwaveguide 120 b of FIG. 6 are reflected from the first mirror 130 a ontoa third waveguide 120 c, which in turn are reflected from a secondmirror 130 b onto a fourth waveguide 120 d. A fabricator may define thewaveguides 120 and mirrors 130 such that not every optical signal isguided by the periscope assembly to a new plane (e.g., terminating asubset of waveguides 120, bending rather than periscoping a subset ofwaveguides 120, allowing a subset of waveguides 120 to runun-redirected). A fabricator may also define the waveguides 120 andmirrors 130 such that some optical signals are not only redirected tonew planes, but to new directions. For example, a periscope assembly mayreceive optical signals along the x-axis in a first plane, and redirectthose optical signals to a second plane along the x-axis, the y-axis, oranother direction.

FIG. 7 illustrates a mirror arrangement 700, according to embodiments ofthe present disclosure. In the mirror arrangement 700 of FIG. 7, opticalsignals carried by a first waveguide 120 a and a second waveguide 120 bare reflected from a first mirror 130 a onto a third waveguide 120 c anda fourth waveguide 120 d, respectively. The optical signals carried bythe third waveguide 120 c are reflected from a second mirror 130 b ontoa fifth waveguide 120 e, and the optical signals carried by the fourthwaveguide 120 d are reflected from a third mirror 130 c onto a sixthwaveguide 120 f. A fabricator may define the waveguides 120 and mirrors130 such that one mirror 130 redirects optical signals in a differentplane and/or direction than another mirror 130 despite being received inthe same plane and/or direction. For example, the optical signalscarried by the first and second waveguides 120 a-b may be received bythe first mirror 130 a in the same direction (e.g., along the x-axis)and be redirected by the second and third mirrors 130 b-c in differentdirections (e.g., along the x-axis and y-axis, respectively).

FIG. 8 illustrates a mirror arrangement 800, according to embodiments ofthe present disclosure. In the mirror arrangement 800 of FIG. 8, opticalsignals carried by a first waveguide 120 a are reflected from a firstmirror 130 a onto a second waveguide 120 b and are reflected from asecond mirror 130 b onto a third waveguide 120 c to change the plane inwhich the optical signal is carried. A fourth waveguide 120 d carriesoptical signals that are reflected by a third mirror 130 c onto a fifthwaveguide 120 e to carry the optical signals in a new direction in theinitial plane. A fabricator may define the waveguides 120 and mirrors130 such that multiple mirrors 130 redirect optical signals received inthe same plane and/or direction are redirected in different planesand/or directions from one another. For example, the optical signalscarried by the first waveguide 120 a and fourth waveguide 120 d may bereceived by the first mirror 130 a and the third mirror 130 c in thesame direction (e.g., along the x-axis) and be redirected in differentdirections and planes from one another.

FIG. 9 illustrates a mirror arrangement 900, according to embodiments ofthe present disclosure. In the mirror arrangement 900 of FIG. 9, fourmirrors 130 a-d are disposed in the substrate to adjust a spacingbetween two light paths as received and as output. For example, a firstdistance 910 a between a first waveguide 120 a and a second waveguide120 b as input may be different than a second distance 910 b between acorresponding fifth waveguide 120 e and sixth waveguide 120 f as output.A fabricator may define the waveguides 120 and mirrors 130 such thatmultiple mirrors 130 redirect optical signals received on waveguides 120arranged in one pattern into a differently spaced version of thatpattern on the same or a different plane and/or direction as thewaveguides 120 are received.

FIG. 10 illustrates a mirror arrangement 1000, according to embodimentsof the present disclosure. In the mirror arrangement 1000 of FIG. 10,two mirrors 130 a-b are disposed in the substrate to adjust a spacingbetween two light paths as received and as output on the same plane. Forexample, a first distance 910 a between a first waveguide 120 a and asecond waveguide 120 b as input may be different than a second distance910 b between a third waveguide 120 c in the second light path and thefirst waveguide 120 a as output. A fabricator may define the waveguides120 and mirrors 130 such that multiple mirrors 130 redirect opticalsignals received on waveguides 120 arranged in one pattern into adifferently spaced version of that pattern on the same or a differentplane and/or direction as the waveguides 120 are received. Accordingly,a fabricator may redefine the relative spacing of two or more lightpaths on the same plane.

The mirror arrangements illustrated in FIGS. 5-10 are provided asnon-limiting examples of some of the ways a fabricator can deploymirrors 130 and waveguides 120 to redirect and rearrange some or all ofthe incoming signal paths into new planes, orders, and/or directions. Afabricator may use more or fewer than the illustrated number ofwaveguides 120 and/or mirrors 130 and may combine, reverse, and modifythe example mirror arrangements as illustrated to meet the use casesparticular to a given periscope assembly application.

FIGS. 11A and 11B illustrate coupling arrangements 1100 a-b for aperiscope assembly 100 and another optical element 1110, such as, forexample, a photonic platform or an optical cable, according toembodiments of the present disclosure.

FIG. 11A illustrates a direct coupling arrangement 1100 a (also referredto as a butt-coupling), in which a light path travels directly through ajoint formed by the mating surface 111 of the periscope assembly 100 andmating surface 1111 of the optical element 1110. As illustrated, theperiscope assembly 100 abuts the optical element 1110, with matingsurfaces 111/1111 perpendicular to the light path formed by thewaveguides that carry optical signals between the periscope assembly 100and the optical element 1110. The waveguides 120 of the periscopeassembly 100 are located at a first height h₁ on a first side (notcoupled with the optical element 1110) and are located at a different,second height h₂ on a second side coupled with the optical element 1110.In the direct coupling arrangement 1100 a, the waveguides 1120 of theoptical element 1110 are linearly arranged to receive light via directtransmission from the waveguides 120 of the periscope assembly 100. Invarious embodiments, lenses, filters, and surface treatments may beapplied on the mating surfaces 111/1111 to aid in direct transfer ofoptical signals.

FIG. 11B illustrates an evanescent coupling arrangement 1100 b in whicha mating surface 111 of the periscope assembly 100 is connected to amating surface 1111 of an optical element 1110, and the light paththrough the periscope assembly 100 is not perpendicular to matingsurfaces 111/1111. Instead, an evanescent region 121 of the waveguides120 is incident to the mating surface 111, which evanescently transfersoptical signals to/from an evanescent region 1121 of the waveguides 1120of the optical element 1110 that are incident to the mating surface1111. The waveguides 120 of the periscope assembly 100 are located at afirst height h₁ on a first side (not coupled with the optical element1110) and drop to a second height h₂ at which the evanescent region 121begins.

FIG. 12 is a flowchart of a method 1200 to deploy a periscope opticalassembly, according to embodiments of the present disclosure.

At block 1210, a fabricator defines one or more mirrors 130 in asubstrate (e.g., a bulk material 110). At block 1220, the fabricatordefines one or more waveguides in the substrate. Although illustrated asbeginning with block 1210 and proceeding to block 1220, in variousembodiments, method 1200 may begin with either of block 1210 or block1220 and proceed to the other, or may begin simultaneously at block 1210and block 1220. Additionally or alternatively, a fabricator may performblock 1210 and block 1220 in alternating iterations (e.g., forming afirst mirror 130 a, then forming one or more waveguides 120, thenforming a second mirror 130 b) or in phases (e.g., performing a firstphase of block 1210, performing block 1220, performing a second phase ofblock 1220).

When forming mirrors 130 (per block 1210), a fabricator may use one ormore of a laser patterning process or an etching process to definemirrors 130 in the substrate. A laser patterning process defines mirrors130 via a change in the material matrix of the substrate that affectsthe reflectivity of the substrate in a designated region, therebydefining a reflective surface 310 with a desired shape and orientationin the substrate. An etching process removes material from the substrateto define a void with one or more surfaces that may be polished or havea surface treatment applied thereto, thereby defining a reflectivesurface 310 with a desired shape and orientation in the substrate. Invarious embodiments, the etching process is preceded by a laserpatterning process that changes the reactivity of a designated region ofthe substrate to a chemical etchant (e.g., via changing the chemicalbond in regions of the material matrix of the substrate). The reflectivesurface 310 receives optical signals carried on one waveguide 120 andredirects those optical signals by a predefined reflective angle 410onto another waveguide 120.

When forming waveguides 120 (per block 1220), a fabricator may use alaser patterning process to define regions in the substrate withdifferent refractive indices than the surrounding material to direct thepropagation of light through the material. The waveguides 120 may haveends that are co-aligned with engagement features defined in thesubstrate to ensure optical coupling with waveguides in other assembliesor components. Similarly, the waveguides 120 may have ends that that areco-aligned with one or more mirrors 130.

In some embodiments, the laser defines where the waveguide pattern islocated simultaneously with where the etching pattern is appliedrelative to the alignment point. In other embodiments, the etchingpattern is applied relative to the alignment point, and the waveguidepattern is later applied relative to the etching pattern (e.g., after achemical etch). In further embodiments, the waveguide pattern is appliedrelative to the alignment point, and the etching pattern is laterapplied relative to the waveguide pattern.

At block 1230, when the fabricator uses a multi-component periscopeassembly (e.g., as in FIG. 2), the fabricator joins the components 210together. In various embodiments, the fabricator may detail thecomponents before joining, which may include dicing the substrate into adesired shape, polishing at least one external surface, applying epoxiesor heat treatments for affixing the components together, and the like.Various alignment features may be included in the components to ensurethat the portions of waveguides 120 defined in different components areoptically aligned with one another. Depending on the design of theperiscope components, the periscope parts can be aligned using active orpassive alignment processes.

At block 1240, the fabricator couples the periscope assembly to one ormore of an optical fiber or a photonic platform. In various embodiments,based on the alignment and pathing of the waveguides 120, the fabricatormay couple the periscope assembly via an evanescent transfer or directtransfer (e.g., a butt coupling) of optical signals to/from the photonicplatform or optical fiber. The fabricator may couple the periscopeassembly and the other optical elements together via epoxies, physicalinterconnects, thermo-compression, or the like. Method 1200 may thenconclude.

In the preceding, reference is made to embodiments presented in thisdisclosure. However, the scope of the present disclosure is not limitedto specific described embodiments. Instead, any combination of thedescribed features and elements, whether related to differentembodiments or not, is contemplated to implement and practicecontemplated embodiments. Furthermore, although embodiments disclosedherein may achieve advantages over other possible solutions or over theprior art, whether or not a particular advantage is achieved by a givenembodiment is not limiting of the scope of the present disclosure. Thus,the preceding aspects, features, embodiments and advantages are merelyillustrative and are not considered elements or limitations of theappended claims except where explicitly recited in a claim(s).

In view of the foregoing, the scope of the present disclosure isdetermined by the claims that follow.

We claim:
 1. An interposer, comprising: a bulk material having a firstside and a second side opposite to the first side; a first optic definedin the bulk material at a first height in the bulk material along anaxis extending between the first side and the second side, wherein thefirst optic is located at a first distance between the first side andthe second side; a second optic defined in the bulk material at a secondheight in the bulk material, different than the first height, along theaxis, wherein the second optic is located at the first distance betweenthe first side and the second side and defines an evanescent regionbetween the second side and the second optic; a first waveguide definedin the bulk material, extending from the first side to the first optic;a second waveguide defined in the bulk material, extending from thesecond optic to the second side; and a third waveguide defined in thebulk material, extending from the first optic to the second optic. 2.The interposer of claim 1, wherein the bulk material is divided into afirst bulk material comprising a first component and a second bulkmaterial comprising a second component; the first component comprising:the first waveguide; the first optic; and a first portion of the thirdwaveguide; the second component comprising: the second waveguide; thesecond optic; and a second portion of the third waveguide; and whereinthe first component is joined to the second component to align the firstportion with the second portion of the third waveguide.
 3. Theinterposer of claim 1, further comprising: a fourth waveguide defined inthe bulk material, extending from the first side to the second side,wherein a first distance between the first waveguide and the fourthwaveguide on the first side is different than a second distance betweenthe second waveguide and the fourth waveguide on the second side.
 4. Theinterposer of claim 1, wherein one or more of the first optic, thesecond optic, the first waveguide, the second waveguide, and the thirdwaveguide are defined by an laser patterning affecting a reflectivity ofthe bulk material.
 5. The interposer of claim 1, wherein one or more ofthe first optic and the second optic are defined via a lithography andetching process and a surface treatment to apply a reflective surfacewithin the bulk material.
 6. The interposer of claim 1, wherein thefirst waveguide travels in a first direction at the first height and thesecond waveguide travels in the first direction at the second height. 7.The interposer of claim 1, further comprising: a third optic defined inthe bulk material at a third height in the bulk material, different thanthe first height and the second height, between the first side and thesecond side; a fourth optic defined in the bulk material at the secondheight in the bulk material between the first side and the second side;a fourth waveguide, running from the first side to the third optic; afifth waveguide, running from the fourth optic to the second side; and asixth waveguide, running from the third optic to the fourth optic. 8.The interposer of claim 7, wherein the first optic and the third opticare mirrors, wherein the first optic has a first reflective angle thatis different than a second reflective angle of the third optic.
 9. Theinterposer of claim 7, wherein the first optic is located at a firstdistance between the first side and the second side and the third opticis located at a second distance between the first side and the secondside, different than the first distance.
 10. A method, comprising:defining a first mirror in a bulk material at a first height; defining asecond mirror in the bulk material at a second height, different thanthe first height; defining a first waveguide in the bulk material,optically connected to the first mirror and a first edge of the bulkmaterial; defining a second waveguide in the bulk material, opticallyconnected to the second mirror and a second edge of the bulk material,different than the first edge, and defining an evanescent region betweenthe second edge and the second mirror; and defining a third waveguide inthe bulk material, optically connected to the first mirror and thesecond mirror to define a light path from the first edge to the secondedge via the first waveguide, the first mirror, the third waveguide, thesecond mirror, and the second waveguide.
 11. The method of claim 10,further comprising: joining a first component to a second component;wherein the first component includes the first mirror, the firstwaveguide, and a first portion of the third waveguide; wherein thesecond component includes the second mirror, the second waveguide, and asecond portion of the third waveguide; and wherein the first componentand the second component are aligned such that when joined, the firstportion of the third waveguide is collinear with the second portion ofthe third waveguide.
 12. The method of claim 10, wherein the definingthe first mirror further comprises: etching a void into the bulkmaterial; and applying a surface treatment to increase a reflectivity ofa face defined by the void.
 13. The method of claim 10, wherein thedefining the second mirror further comprises: patterning, via a laser, aprism having a reflective surface in the bulk material.
 14. A system,comprising: a first waveguide defined in a first plane of a bulkmaterial; a second waveguide defined in a second plane of the bulkmaterial, parallel to the first plane; a third waveguide defined in athird plane of the bulk material that intersects the first plane and thesecond plane; a first mirror defined at a first intersection of thefirst plane and the third plane and optically connected to the firstwaveguide and the third waveguide; and a second mirror defined at asecond intersection of the third plane and the second plane andoptically connected to the third waveguide and the second waveguide; andwherein the second waveguide defines an evanescent region between thesecond mirror and a surface of the bulk material.
 15. The system ofclaim 14, further comprising: a first component, including: the firstwaveguide; the first mirror; a first portion of the third waveguide; asecond component, including: the second waveguide; the second mirror;and a second portion of the third waveguide; and wherein the firstcomponent is bonded with the second component such that the firstportion of the third waveguide and the second portion of the thirdwaveguide are linearly aligned in the third plane.
 16. The system ofclaim 14, further comprising: a fourth waveguide, defined in a fourthplane in the bulk material, parallel to the first plane; a fifthwaveguide defined in the second plane of the bulk material; a sixthwaveguide defined in a fifth plane of the bulk material that intersectsthe fourth plane and the second plane; a third mirror defined at a thirdintersection of the fourth plane and the fifth plane and opticallyconnected to the fourth waveguide and the sixth waveguide; and a fourthmirror defined at a fourth intersection of the fifth plane and thesecond plane and optically connected to the sixth waveguide and thefifth waveguide.
 17. The system of claim 14, wherein a first reflectiveangle between the first waveguide and the third waveguide is 90 degrees;and wherein a second reflective angle between the second waveguide andthe third waveguide is 90 degrees.
 18. The system of claim 14, whereinthe first mirror is a reflective surface defined in a void etched intothe bulk material.
 19. The system of claim 14, wherein the second mirroris a reflective surface of a prism structure defined via laserpatterning of a material matrix of the bulk material.